It cannot be any worse than designating a sensor as "aps-c" size. How ridiculous can we get - but most know what you are talking about, hey - just how big is an aps-c sensor?

APS-C, APS-H are terms used by makers themselves. Nikon says DX because they like to stand in their own little corner, although they too use "full frame" and FX interchangeably.

During the long and initially slow but growing exponentially faster transition from film to digital the largest part of the camera buying market - consumers - needed to be sold products, and to sell products you need to be able to talk about them.

Maybe those behind "APS-C" were envious of the 4/3 appellation - how cool is that, don't even specify the sensor size, just the aspect ratio? They couldn't call full frame 2/3 because that would seem smaller, and 3/2 likewise seems smaller. Win: 4/3, but still, we need a name for this smaller than 35mm larger than 4/3 sensor. Hey, why not name it after those infernal Advanced Photo System film cameras we threw out last year?

It seems some bright light (?) decided that nominating a smaller than 35mm format sensor as "APS-something" - heck, call it anything but get on with it - was not a bad idea in the pursuit of finding a way of explaining to consumers that they had to buy what was on the truck, a camera with a smaller sensor area than the film they shot yesterday, bringing with it the sometimes unhappy side-effect of changing the apparent focal length/field of view of all the lenses they'd used over years.